Audacity has built in accessibility features to assist vision-impaired radio producers.
A very important feature of Audacity is the ability to fully manipulate the selection using the keyboard.
Screen reader access works very well on Windows. Mac OS X screen reader support now requires considerable adjustment following a transition to wxWidgets 3, but a 2.1.1 accessible build is available on our Mac OS X downloads page. Screen reader support still needs further development on Linux.
See the Audacity Wiki here: http://wiki.audacityteam.org/wiki/Audacity_for_blind_users
There is also and Audacity For The Blind email list here: http://www.freelists.org/list/audacity4blind